Imparting P vacancy in Ni-doped CoP derived from double-ligand MOF strategy as robust electrocatalyst

Abstract

Efficient and stable bifunctional electrocatalysts are pivotal for electrocatalytic water splitting applications. Here, a dual-ligand (dithiooxamide and 2-methylimidazole) MOF-derived Ni–CoP has been successfully prepared. The 1D nanowire hydroxide is employed as template precursor to obtain the regular morphology of MOFs. The Co and P in dual-ligand MOF-derived Ni-CoPv exhibits different electronic state compared to single-ligand (2-methylimidazole) MOF-derived Ni–CoP. Importantly, the Ni-CoPv possesses larger number of P vacancy and poor crystal degree. Based on above-mentioned results, Ni-CoPv exhibits superior activity for HER, which requires only 263 mV to reach 500 mA cm−2 without IR correction and shows long-term stability. The HER process for Ni-CoPv follows the V–H mechanism. As a bifunctional electrocatalyst, Ni-CoPv electrode requires 1.57 V to reach 10 mA cm−2 for the water splitting. Compared to Ni–CoP-M derived from single-ligand MOF, Ni-CoPv exhibits higher intrinsic activity HER/OER. We pave a simple way for the construction of a kind of CoP catalyst with rich P vacancies.